1. Field of the Invention
The present invention relates to a head gimbal assembly (HGA) including a head slider having a magnetic head element, a micro-actuator for minutely driving (fine positioning) the head element and a suspension on which the head slider and the micro-actuator are mounted, a magnetic disc drive device equipped with the head gimbal assembly and a method of manufacturing the head gimbal assembly.
2. Description of the Related Art
A disc drive device is designed so that recording/reproduction of information is carried out on a disc by a magnetic head formed on a head slider. The head slider is mounted on a support member called as a suspension, and it is moved so as to face the magnetic disc while following the driving of the suspension by a voice coil motor (hereinafter referred to as “VCM”).
In connection with large-capacity and high-density recording design for magnetic disc devices, increase of the density in the disc radial direction (track width direction) has been recently promoted, and thus it has been hitherto difficult to perform the accurate positioning of the magnetic head by merely controlling the voice coil motor (VCM).
Therefore, a technique using a driving mechanism called as a micro-actuator has been proposed as one method of implementing the precise positioning of the magnetic head. According to this technique, in addition to VCM, an actuator mechanism is mounted to be nearer to a magnetic head slider side than VCM, and minute and precise positioning which cannot be implemented by VCM is carried out by the micro-actuator. The micro-actuator is disclosed in JP-A-2004-158163, for example.
A fabrication process for a head gimbal assembly having this type of micro-actuator mounted therein has been hitherto carried out in the following order.
First, a head slider is disposed between the arms of a micro-actuator, and each arm and the header slider are bonded to each other by an adhesive. Thereafter, the micro-actuator to which the head slider adheres is mounted on a suspension, and then a necessary electrical connecting work is carried out on the micro-actuator and the head slider.
In the above-described fabrication order, however, the head slider must be handled in many steps, and thus the magnetic head formed on the head slider may be damaged by electrostatic discharge (ESD) or the like with high probability, which causes reduction in yield.
Furthermore, the handling of the head slider is required to be carried out in a high-precision clean room in order to prevent adherence of dust or moisture to the magnetic head. In the conventional manufacturing process, the head slider is first adhesively bonded to the micro-actuator, and thus the manufacturing steps must be carried out in a high-precision clean room after the first step of adhesively bonding the head slider to the micro-actuator. Therefore, a high equipment investment has been hitherto required to provide a clean room.
Still furthermore, when the head slider is defective, it is required to detach the micro-actuator from the suspension, remove the head slider from the micro-actuator thus detached and then re-fabricating these elements, and thus rework is cumbersome. In addition, the same work is required to withdraw defective head sliders, and thus the withdrawing work is also cumbersome as in the case of the rework.